Hosea 4:17

Since Ephraim (lit. fruitful), the largest tribe in the Northern Kingdom that stood for the whole nation, had abandoned her Shepherd for idols, He called others to leave her alone also. He would abandon her to the judgment that would come inevitably from pursuing sin (cf. Romans 1:18-32). Ephraim had become incorrigible.

"By referring to the North as Ephraim Hosea reminds Israel that, as we saw in the story of Jeroboam I, it owed its very existence to Ephraim’s jealousy of Judah with its God-given institutions of the Jerusalem temple and the Davidic monarchy." [Note: Ellison, p. 115.]